Impacto da crise económica e financeira na performance das PME’s

Dissertação de mestrado em Economia Monetária Bancária e FinanceiraA crise económica e financeira foi um dos marcos mais trágicos para a economia nacional, causando vários constrangimentos a nível macroeconómico. A maioria das empresas nacionais enfrentaram graves problemas quando o colapso económico se fez ressentir e, visto que, a principal fonte de financiamento das empresas é o recurso ao capital alheio é importante avaliar as consequências que a crise trouxe, nomeadamente na restrição ao crédito concedido às empresas. Uma vez que as empresas mais dependentes do crédito bancário são as empresas de pequena dimensão, e sendo estas as principais responsáveis pelo tecido empresarial português é necessário perceber em que sentido a crise económica e financeira afetou a performance destas empresas. Posto isto, os objetivos principais da presente dissertação são: o de avaliar o impacto que a crise teve na performance das empresas, quer sejam PME’s quer sejam empresas de grande dimensão; e se as empresas mais dependentes do financiamento alheio foram mais afetadas do que as outras. Para tal, teremos de averiguar quais os determinantes da performance das empresas, sendo esta outra questão de investigação. Assim, com base na literatura sobre os determinantes da performance das empresas, este estudo analisa a relação entre a performance e as variáveis explicativas: idade, dimensão, tangibilidade, liquidez, financiamento alheio, capital próprio e crise. A amostra é composta por 5500 empresas observadas no período compreendido entre 2007 e 2016. Em geral, os resultados sugerem que são as grandes empresas que conseguem obter uma melhor performance quando não estamos perante um período de crise e, contrariamente às nossas expectativas, são as empresas de menor dimensão, isto é, as PME’s as que conseguem obter uma performance superior em períodos de crise. Além disso, verificamos que a variável crise não é estatisticamente significativa no estudo da performance das empresas sendo o seu impacto importante uma vez que afeta a performance por via das outras variáveis explicativas. A dimensão das empresas e a liquidez têm um impacto positivo na performance das empresas. Contudo, os resultados da estimação mostram que a idade, o financiamento alheio e o capital próprio influenciam negativamente o desempenho das empresas. Por fim, a tangibilidade varia consoante as variáveis explicativas incluídas no modelo, apresentando um efeito ambíguo.The economic and financial crisis is one of the most tragic phenomenon for a national economy, causing various constraints at the macroeconomic portuguese level. Most national enterprises had serious problems when the global financial and economics crisis erupted. The small and medium-sized firms are the most dependent of bank credit and they are the responsible for the Portuguese business market. Thus, it is necessary understand how economic and financial crisis affected a firms performance. This paper explores the impact of the crisis on the performance of SMEs and large companies and if were the SME’s the more dependent of bank credit. Furthermore, this paper study the determinants of firm perfomance. Based on recent literature about the determinants of firm performance, this study analyzes a relationship between a performance and age, debt, shareholdr’s equity, size, tangibility, liquidity, and eocnomics crisis. This thesis is based on a sample of 5500 North Portuguese firms for the period 2007- 2016 for the textiles and clothing sector. The empirical evidence indicates that the large companies had a better performance when they weren’t affected by crisis, and, contrary to the spectacle, the SME’s were the fims with better performance when they were in the period of the crisis. In addition, our findings reveal that the variable crisis are not relevant in explaining the firms performance in textils and clothing sector, however, this variable is important because the impact of crisis affects a performance through the other explanatory variables. Our empirical results show that the debt, age and shareholder’s equity influence performance negatively. We also verified that the performance was growing with size and liquidity. Finally, we saw that the impact of tangibility was modified with the variables in the regression

Development of tools to support the production planning in a textile company

Technologies are constantly evolving and so with advances in industry 4.0, its intelligent technologies with production planning and control (PPC) give rise to a smart PPC. Nowadays, one of the fundamental systems in a company is the ERP, since it allows the integration of various information from the different areas belonging to an organization, which allows access to data in real time, among other things. Through a work carried out in a textile company, it was noticeable the need to develop a tool to support its installed ERP system and the respective data control. Thus, it is noted that PPC systems, which include the integration of all areas of a company, must be adapted to its environment, work method and characteristics. With the application of this tool, it was possible to perceive an increase in efficiency and speed in obtaining the desired results, being that it is still under development and could evolve even more.FCT - Fundação para a Ciência e a Tecnologia(UIDB/00319/2020

Inhibition of Specific NF-κB Activity Contributes to the Tumor Suppressor Function of 14-3-3σ in Breast Cancer

14-3-3σ is frequently lost in human breast cancers by genetic deletion or promoter methylation. We have now investigated the involvement of 14-3-3σ in the termination of NF-κB signal in mammary cells and its putative role in cancer relapse and metastasis. Our results show that 14-3-3σ regulates nuclear export of p65-NF-κB following chronic TNFα stimulation. Restoration of 14-3-3σ in breast cancer cells reduces migration capacity and metastatic abilities in vivo. By microarray analysis, we have identified a genetic signature that responds to TNFα in a 14-3-3σ-dependent manner and significantly associates with different breast and other types of cancer. By interrogating public databases, we have found that over-expression of this signature correlates with poor relapse-free survival in breast cancer patients. Finally, screening of 96 human breast tumors showed that NF-κB activation strictly correlates with the absence of 14-3-3σ and it is significantly associated with worse prognosis in the multivariate analysis. Our findings identify a genetic signature that is important for breast cancer prognosis and for future personalized treatments based on NF-κB targeting

Development of a tool to support production planning and control in a textile company

Dissertação de mestrado em Engenharia Industrial (área de especialização em Gestão Industrial)A presente dissertação foi realizada no âmbito do Mestrado em Engenharia Industrial – Ramo Gestão Industrial na Universidade do Minho, em contexto industrial numa empresa do setor têxtil. O principal objetivo deste projeto consistiu em desenvolver uma ferramenta para apoiar no planeamento e controlo da produção (PCP). Inicialmente foi elaborada uma revisão bibliográfica dos principais temas que envolvem este projeto para uma melhor compreensão dos conceitos, como PCP, sistema ERP (Enterprise Resource Planning), gestão da informação e PCP inteligente. As tecnologias estão em constante evolução e, por isso, com os avanços da indústria 4.0, as suas tecnologias inteligentes integradas com o PCP dão origem a um PCP inteligente. Atualmente, um dos sistemas fundamentais numa empresa é o ERP, visto que permite a integração de várias informações das diferentes áreas de uma empresa, o que permite o acesso a dados em tempo real, entre outros. Numa fase de diagnóstico foi feita uma caracterização da empresa, assim como uma análise crítica da situação atual onde foram identificados problemas, nomeadamente o facto de se realizar um planeamento manual quando as datas solicitadas pelos clientes não estão de acordo com as datas definidas pelo sistema. Tornou-se percetível a necessidade de desenvolver uma ferramenta de apoio ao sistema ERP instalado na empresa, e respetivo controlo dos dados. Após o reconhecimento dos problemas, procedeu-se à implementação da proposta de melhoria, que consistiu no desenvolvimento de uma ferramenta em ficheiro Excel que permite realizar o planeamento da produção de forma mais automática, ou seja, verificou-se a digitalização do PCP que era efetuado manualmente. Posto isto, foi realizada uma análise aos resultados obtidos, em que se constatou uma redução de cerca de 45% no tempo despendido a planear e foi possível observar um aumento na eficiência e rapidez na obtenção dos resultados desejados. Neste momento, a ferramenta encontra-se numa fase de implementação no sistema SAP.The present dissertation was carried out within the scope of the Master’s degree in Industrial Engineering – Industrial Management at the University of Minho, in an industrial context in a company in the textile sector. The main objective of this project was to develop a tool to support production planning and control (PPC). Initially, a bibliographic review of the main themes involving this project was prepared for a better understanding of concepts, such as PPC, ERP (Enterprise Resource Planning) system, information management and smart PPC. Technologies are constantly evolving and so with advances in industry 4.0, its intelligent technologies with PPC give rise to a smart PPC. Nowadays, one of the fundamental systems in a company is the ERP, since it allows the integration of various information from the different areas belonging to an organization, which allows access to data in real time, among other. In a diagnostic phase, a characterization of the company was made, as well as a critical analysis of the current situation where problems were identified, namely the fact of carrying out a manual planning when the dates requested by the customers do not agree with the dates defined by the system. It was noticeable the need to develop a tool to support its installed ERP system and the respective data control. After recognizing the problems, the improvement proposal was implemented, which consisted in the development of a tool in an Excel file that allows to carry out the production planning in a more automatic way, that is, the PPC was scanned, which was performed manually. That said, an analysis of the results was carried out, in which there was a reduction of about 45% in the time spent planning and it was possible to observe an increase in efficiency and speed in obtaining the desired results. At the moment, the tool is in the implementation phase in the SAP system

Development of fibrous structures for brain phantoms

Tese de Doutoramento - Programa Doutoral em Engenharia BiomédicaIn Europe, 75,000 people die each year from traumatic brain injuries, mainly caused by traffic accidents. In the United States, 1.7 million/year cases of traumatic brain injuries occur and only in 5-30% of these cases the damages are detected by current imaging techniques, as computed tomography and magnetic resonance imaging. High-Definition Fiber Tractography is a novel modality of magnetic resonance imaging, based on diffusion technology of water molecules through brain tissue, which provides highly detailed images of the brain. This imaging technique allows detecting the exact local of damage in an axon as X-Ray allows identifying the local where a bone is broken. The inexistence of a phantom that rigorously mimics the human brain hinders the possibility of testing, calibrating and validating these medical imaging techniques. Most research in this area suffers from a huge gap in key points, such as the size limit and geometry used to mimic the human brain axons. The aim of this PhD project was to assess the application of synthetic fibrous materials, which mimic human axons of brain white matter in terms of geometry, on the development of an anisotropic brain phantom, as similar as possible to the human brain white matter, which could be employed on the validation and calibration of brain diffusion imaging, based on magnetic resonance imaging, including the novel neuroimaging technique: the High- Definition Fiber Tractography imaging. To this end, hollow multifilament yarns made of polypropylene and polyamide and coaxial polycaprolactone fibers, produced by electrospinning, were chosen for the undertaken studies, due to its tube-like geometry, with dimensions close to the human axons. To obtain the desired dimensions, comparable to human axons, three different technologies were tested: polypropylene and polyamide hollow multifilament commercial yarns obtained by melt spinning technique; postproduction stretching of the previously mentioned hollow yarns using a laboratorial filament extrusion line; and, production of coaxial polycaprolactone fibers by electrospinning. Characterization of the hollow multifilament yarns regarding physical, chemical and mechanical properties was performed. In order to achieve the different configuration that human axons present in white matter of the human brain, fibrous structures were developed based on polypropylene hollow multifilament yarns due to some of their interesting properties comparatively to polyamide. Braided structures, narrow fabrics and embroidery technology showed to be a good choice to mimic the parallel configuration of the human axons, crossing zones and complex patterns existing in the white matter. The different types of water motion that occur in the axons of human white matter were verified in the fibrous materials by fluorescence microscopy. At the end, the yarns were scanned in magnetic resonance equipment and analyzed using High-Definition Fiber Tractography. Polypropylene hollow multifilament yarns showed to be an outstanding option to mimic white matter human axons in the development of anisotropic brain phantoms to validate and make the quality control of the neuroimaging techniques. Furthermore, High-Definition Fiber Tractography presented highly detailed images of the polypropylene yarns. The results presented in this work are novel and promising since there is no literature that focuses on the study of material properties that mimic properly the human axons of brain white matter. These works have been performed in the framework of the project: “High-Definition MRI Fiber Tracking and Computational Phantom Quality Measurement and Assessment” coordinated by Walter Schneider, at University of Pittsburgh, USA, whose research was devoted to the development of the first phantom for the validation of the novel High-Definition Fiber Tractography imaging.Na Europa, 75.000 pessoas morrem, anualmente, devido a traumatismos cranioencefálicos, principalmente, causados por acidentes rodoviários. Nos Estados Unidos, ocorrem, por ano, 1.7 milhões de casos e, apenas, em 5 a 30% destes casos, os danos são detetados pelas técnicas de neuroimagem mais utilizadas, como a tomografia computorizada e a ressonância magnética. High-Definition Fiber Tractography (Tractografia de fibras em alta definição) é uma nova modalidade de imagem por ressonância magnética, baseada na difusão das moléculas de água através do tecido cerebral, que fornece imagens altamente detalhadas do cérebro. Esta ferramenta de imagem permite detetar o local exato de um dano num axónio tal como o Raio-X identifica o local onde um osso está fraturado. A inexistência de um modelo adequadamente aproximado ao cérebro humano impede a possibilidade de testar, calibrar e validar estas técnicas de imagem médica. A maioria das pesquisas nesta área sofre uma enorme lacuna em pontos-chave, como o limite de tamanho e geometria utilizada para imitar os axónios do cérebro humano. O objetivo deste projeto foi avaliar a aplicação de materiais fibrosos sintéticos, que imitam os axónios humanos da matéria branca do cérebro em termos de geometria, para o desenvolvimento de um fantoma anisotrópico, o mais semelhante possível à matéria branca do Homem, que poderá ser utilizado na validação e calibração de técnicas de neuroimagem baseadas na difusão das moléculas de água no cérebro, com base em imagens de ressonância magnética, incluindo a nova técnica de neuroimagem: High-Definition Fiber Tractography. Para tal, foram utilizados fios multifilamento ocos de polipropileno e poliamida e fibras coaxiais de policaprolactona, produzidas por electrospinning, devido à sua geometria tubular, com dimensões próximas aos axónios. Para obter as dimensões desejadas, comparáveis aos axónios humanos, três tecnologias foram testadas: fios multifilamento ocos comerciais de polipropileno e poliamida obtidos por melt spinning; estiramento pós-produção dos fios ocos mencionados anteriormente, utilizando uma linha laboratorial de extrusão de filamentos; e, a produção de fibras de policaprolactona coaxiais através de electrospinning. Os fios multifilamento ocos foram caracterizados a nível físico, químico e mecânico. Com o objetivo de reproduzir as diferentes configurações dos axónios na matéria branca, foram desenvolvidas estruturas fibrosas utilizando os fios multifilamento ocos de polipropileno, uma vez que este material apresentou propriedades mais adequadas, comparativamente às da poliamida. Estruturas entrançadas, tecidos estreitos e bordados mostraram ser uma boa escolha para mimetizar a configuração paralela e zonas de cruzamentos de axónios, assim como, certos padrões complexos que existem na matéria branca. Os diferentes tipos de movimento da água que ocorrem nos axónios humanos foram verificados nos materiais fibrosos, através de microscopia de fluorescência. No final, os filamentos foram mapeados, através de ressonância magnética, e, os dados foram, posteriormente, analisados através de High-Definition Fiber Tractography. Os filamentos ocos de polipropileno mostraram ser uma excelente opção para mimetizar os axónios humanos da matéria branca, na materialização de modelos cerebrais anisotrópicos para validação e controlo de qualidade das técnicas de neuroimagem. Igualmente, a nova modalidade de imagem High-Definition Fiber Tractography apresentou imagens altamente detalhadas dos fios de polipropileno. Os resultados apresentados neste trabalho são novos e promissores, pois não há literatura focada no estudo das propriedades dos materiais que mimetizam, adequadamente, os axónios humanos da matéria branca do cérebro. Estes trabalhos foram realizados no âmbito do projeto “ High-Definition MRI Fiber Tracking and Computational Phantom Quality Measurement and Assessment", coordenado pelo professor Walter Schneider, da Universidade de Pittsburgh, EUA, cuja pesquisa foi dedicada ao desenvolvimento do primeiro fantoma para a validação da nova modalidade de neuroimagem High-Definition Fiber Tractography

A review on thermal protection

In a situation where an individual is under an extreme environment, clothing may be a decisive factor in his survival. In order to protect the individual from his surrounding harsh environment, clothing must promote the thermal insulation providing the required level of protection. The choice of clothing materials may undergo various approaches, including materials consisting of intrinsically fire-retardant fibers, such as aramids, or materials in which heat-resistant additives or finishes may be applicate (1). A solution may also be the combination of layers: usually a dense and heavy layer surface coated by an aluminum layer in order to promote thermal insulation. Weight is the most important restriction to be considered, as may condition the user's mobility in addition to becoming much more uncomfortable in hot environments (2). In this review, new technologies to provide thermal protection and comfort are presented.info:eu-repo/semantics/publishedVersio

Accuracy of three electronic apex locators in the presence of different irrigating solutions

The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9% saline solution and 1% sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs